Aspects of this disclosure relate generally to telecommunications, and more particularly to techniques for multimedia broadcast multicast service transmissions in unlicensed spectrum.
Wireless communications networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, and the like. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources.
A wireless communications network may include a number of network entities. The network entities of wireless wide area network (WWAN), such as a cellular network, may include a number of base stations, such as NodeBs (NBs) or evolved NodeBs (eNBs). The network entities of a wireless local area network (WLAN) may include a number of WLAN network entities, such as Wi-Fi nodes. Each network entity may support communication for a number of user equipments (UEs) or wireless stations and may often communicate with multiple UEs at the same time. Similarly, each UE may communicate with a number of network entities, and may sometimes communicate with multiple network entities and/or network entities employing different access technologies. A network entity may communicate with a UE via downlink and uplink. The downlink (or forward link) refers to the communication link from the network entity to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the network entity.
As cellular networks become more congested, operators are beginning to look at ways to increase capacity. One approach may include the use of WLANs to, for example, offload some of the traffic and/or signaling of a cellular network. WLANs (or Wi-Fi networks) are attractive because, unlike cellular networks that operate in a licensed spectrum, Wi-Fi networks generally operate in an unlicensed or shared spectrum (e.g., unlicensed spectrum). However, access to unlicensed spectrum may need coordination to ensure that network entities of the same or different operator deployments, using the same or different techniques for accessing the unlicensed spectrum, can co-exist and make effective use of the unlicensed spectrum.
Methods are needed to provide efficient and improved process for maintaining synchronization among a plurality of network entities engaged in joint transmissions on an unlicensed spectrum. In certain instances, if one of the network entities accesses the unlicensed spectrum after a resynchronization boundary and while one or more other nodes are already engaged in joint transmissions interference may occur. Thus, improvements in maintaining synchronization among network entities in unlicensed spectrum during wireless communication are desired.